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ee.Classifier.libsvm

创建一个空的支持向量机分类器。

用法	返回
`ee.Classifier.libsvm(decisionProcedure, svmType, kernelType, shrinking, degree, gamma, coef0, cost, nu, terminationEpsilon, lossEpsilon, oneClass)`	分类器

参数	类型	详细信息
`decisionProcedure`	字符串，默认值：“投票”	用于分类的决策程序。可以是“投票”或“边际”。不用于回归。
`svmType`	字符串，默认值：“C_SVC”	SVM 类型。`C_SVC`、`NU_SVC`、`ONE_CLASS`、`EPSILON_SVR` 或 `NU_SVR` 中的一个。
`kernelType`	字符串，默认值：“LINEAR”	内核类型。LINEAR（u′×v）、POLY（(γ×u′×v + coef₀)ᵈᵉᵍʳᵉᵉ）、RBF（exp(-γ×\|u-v\|²)）或 SIGMOID（tanh(γ×u′×v + coef₀)）之一。
`shrinking`	布尔值，默认值：true	是否使用收缩启发法。
`degree`	整数，默认值：null	多项式的次数。适用于 POLY 核。
`gamma`	浮点数，默认值：null	内核函数中的 Gamma 值。默认为特征数量的倒数。适用于 POLY、RBF 和 SIGMOID 核。
`coef0`	浮点数，默认值：null	核函数中的 coef₀ 值。默认值为 0。适用于 POLY 和 SIGMOID 核。
`cost`	浮点数，默认值：null	费用 (C) 参数。默认为1。仅对 C-SVC、epsilon-SVR 和 nu-SVR 有效。
`nu`	浮点数，默认值：null	nu 参数。默认为 0.5。仅对 nu-SVC、单类 SVM 和 nu-SVR 有效。
`terminationEpsilon`	浮点数，默认值：null	终止条件容差 (e)。默认值为 0.001。仅对 epsilon-SVR 有效。
`lossEpsilon`	浮点数，默认值：null	损失函数中的 epsilon (p)。默认值为 0.1。仅对 epsilon-SVR 有效。
`oneClass`	整数，默认值：null	单类 SVM 中要训练的训练数据类别。默认值为 0。仅对单类 SVM 有效。可能的值包括 0 和 1。分类器输出为二元 (0/1)，对于确定属于相应类别的数据，该输出将与此类别值匹配。

示例

代码编辑器 (JavaScript)

// A Sentinel-2 surface reflectance image, reflectance bands selected,
// serves as the source for training and prediction in this contrived example.
var img = ee.Image('COPERNICUS/S2_SR/20210109T185751_20210109T185931_T10SEG')
              .select('B.*');

// ESA WorldCover land cover map, used as label source in classifier training.
var lc = ee.Image('ESA/WorldCover/v100/2020');

// Remap the land cover class values to a 0-based sequential series.
var classValues = [10, 20, 30, 40, 50, 60, 70, 80, 90, 95, 100];
var remapValues = ee.List.sequence(0, 10);
var label = 'lc';
lc = lc.remap(classValues, remapValues).rename(label).toByte();

// Add land cover as a band of the reflectance image and sample 100 pixels at
// 10 m scale from each land cover class within a region of interest.
var roi = ee.Geometry.Rectangle(-122.347, 37.743, -122.024, 37.838);
var sample = img.addBands(lc).stratifiedSample({
  numPoints: 100,
  classBand: label,
  region: roi,
  scale: 10,
  geometries: true
});

// Add a random value field to the sample and use it to approximately split 80%
// of the features into a training set and 20% into a validation set.
sample = sample.randomColumn();
var trainingSample = sample.filter('random <= 0.8');
var validationSample = sample.filter('random > 0.8');

// Train an SVM classifier (C-SVM classification, voting decision procedure,
// linear kernel) from the training sample.
var trainedClassifier = ee.Classifier.libsvm().train({
  features: trainingSample,
  classProperty: label,
  inputProperties: img.bandNames()
});

// Get information about the trained classifier.
print('Results of trained classifier', trainedClassifier.explain());

// Get a confusion matrix and overall accuracy for the training sample.
var trainAccuracy = trainedClassifier.confusionMatrix();
print('Training error matrix', trainAccuracy);
print('Training overall accuracy', trainAccuracy.accuracy());

// Get a confusion matrix and overall accuracy for the validation sample.
validationSample = validationSample.classify(trainedClassifier);
var validationAccuracy = validationSample.errorMatrix(label, 'classification');
print('Validation error matrix', validationAccuracy);
print('Validation accuracy', validationAccuracy.accuracy());

// Classify the reflectance image from the trained classifier.
var imgClassified = img.classify(trainedClassifier);

// Add the layers to the map.
var classVis = {
  min: 0,
  max: 10,
  palette: ['006400' ,'ffbb22', 'ffff4c', 'f096ff', 'fa0000', 'b4b4b4',
            'f0f0f0', '0064c8', '0096a0', '00cf75', 'fae6a0']
};
Map.setCenter(-122.184, 37.796, 12);
Map.addLayer(img, {bands: ['B11', 'B8', 'B3'], min: 100, max: 3500}, 'img');
Map.addLayer(lc, classVis, 'lc');
Map.addLayer(imgClassified, classVis, 'Classified');
Map.addLayer(roi, {color: 'white'}, 'ROI', false, 0.5);
Map.addLayer(trainingSample, {color: 'black'}, 'Training sample', false);
Map.addLayer(validationSample, {color: 'white'}, 'Validation sample', false);

Python 设置

如需了解 Python API 和如何使用 geemap 进行交互式开发，请参阅 Python 环境页面。

import ee
import geemap.core as geemap

Colab (Python)

# A Sentinel-2 surface reflectance image, reflectance bands selected,
# serves as the source for training and prediction in this contrived example.
img = ee.Image(
    'COPERNICUS/S2_SR/20210109T185751_20210109T185931_T10SEG'
).select('B.*')

# ESA WorldCover land cover map, used as label source in classifier training.
lc = ee.Image('ESA/WorldCover/v100/2020')

# Remap the land cover class values to a 0-based sequential series.
class_values = [10, 20, 30, 40, 50, 60, 70, 80, 90, 95, 100]
remap_values = ee.List.sequence(0, 10)
label = 'lc'
lc = lc.remap(class_values, remap_values).rename(label).toByte()

# Add land cover as a band of the reflectance image and sample 100 pixels at
# 10 m scale from each land cover class within a region of interest.
roi = ee.Geometry.Rectangle(-122.347, 37.743, -122.024, 37.838)
sample = img.addBands(lc).stratifiedSample(
    numPoints=100, classBand=label, region=roi, scale=10, geometries=True
)

# Add a random value field to the sample and use it to approximately split 80%
# of the features into a training set and 20% into a validation set.
sample = sample.randomColumn()
training_sample = sample.filter('random <= 0.8')
validation_sample = sample.filter('random > 0.8')

# Train an SVM classifier (C-SVM classification, voting decision procedure,
# linear kernel) from the training sample.
trained_classifier = ee.Classifier.libsvm().train(
    features=training_sample,
    classProperty=label,
    inputProperties=img.bandNames(),
)

# Get information about the trained classifier.
display('Results of trained classifier', trained_classifier.explain())

# Get a confusion matrix and overall accuracy for the training sample.
train_accuracy = trained_classifier.confusionMatrix()
display('Training error matrix', train_accuracy)
display('Training overall accuracy', train_accuracy.accuracy())

# Get a confusion matrix and overall accuracy for the validation sample.
validation_sample = validation_sample.classify(trained_classifier)
validation_accuracy = validation_sample.errorMatrix(label, 'classification')
display('Validation error matrix', validation_accuracy)
display('Validation accuracy', validation_accuracy.accuracy())

# Classify the reflectance image from the trained classifier.
img_classified = img.classify(trained_classifier)

# Add the layers to the map.
class_vis = {
    'min': 0,
    'max': 10,
    'palette': [
        '006400',
        'ffbb22',
        'ffff4c',
        'f096ff',
        'fa0000',
        'b4b4b4',
        'f0f0f0',
        '0064c8',
        '0096a0',
        '00cf75',
        'fae6a0',
    ],
}
m = geemap.Map()
m.set_center(-122.184, 37.796, 12)
m.add_layer(
    img, {'bands': ['B11', 'B8', 'B3'], 'min': 100, 'max': 3500}, 'img'
)
m.add_layer(lc, class_vis, 'lc')
m.add_layer(img_classified, class_vis, 'Classified')
m.add_layer(roi, {'color': 'white'}, 'ROI', False, 0.5)
m.add_layer(training_sample, {'color': 'black'}, 'Training sample', False)
m.add_layer(
    validation_sample, {'color': 'white'}, 'Validation sample', False
)
m

ee.Classifier.libsvm 使用集合让一切井井有条 根据您的偏好保存内容并对其进行分类。

示例

代码编辑器 (JavaScript)

Colab (Python)

ee.Classifier.libsvm